1. Field of the Invention
The present invention relates to a photo-sensing device, and more particularly to an infrared light detecting apparatus and the detecting method thereof capable of effectively detecting infrared light having longer wavelength in light.
2. Description of the Related Art
In recent years, optical sensors applications become very popular in electronic products. For example, ambient light sensors (ALS), proximity sensors and color RGB sensors are applied to smart phones, desktop computers, laptop computers, tablet computers, liquid crystal displayer (LCD), plasma TVs, optical analyzers, lights, ATM machines and Kiosh stations that need to detect specific light sources.
Taking the ambient light sensors applied to the smart phone for example, the ambient light sensor can detect the ambient light around the smart phone to allow the smart phone to adjust the brightness of the display in accordance with the intensity of ambient light, thereby extending the standby time of the smart phone. However, the light emitted by the light sources, such as incandescent lamps, sunlight or halogen lamps, often contains a very strong infrared portions having longer wavelength. Consequently, even the most sophicated ambient light sensor system may suffer noise problem contributed by the infrared light, which reduces the accuracy thereof. Similarly, other light sensor systems may also suffer from the same infrared noise. Therefore, designing an effective infrared light detecting apparatus, which operates as a correction or cancellation factor for the optical sensing system, and easily integrated with other mainstream integrated circuit manufacturing process like CMOS, is an important issue that needs to be overcome.